From DE 10 2008 036 331 B3, there is known a jet device for spraying surfaces to be treated with a mixed stream of pressurized gas and dry ice pellets. This comprises a screw conveyor which presses CO2 snow through a die in order thereby to produce CO2 pellets. Compressor devices in the form of gear compressors are known, for example, from DE 21 06 477 B2 and EP 0429 698 A1.
A disadvantage of the known spraying devices is, in particular, that with the compressor device used, only a very inhomogeneous mixture of differently-sized CO2 pellets can be produced.